32 Report of the American » 



all of the ova will become iiupregnated. The pan or vessel containing 

 the eggs is then laid aside for a short time, and in order to ascer- 

 tain the quantit}' the}' are measured out by means of a little measure, 

 made to contain a certain number, and then placed upon the breeding 

 tra3's ; they are then laid in the hatching troughs, through which a con- 

 stant flow of water from the stream is made to run. Here the eggs are 

 allowed to remain during the whole period of their incubation, namely, 

 from October and November till the following April and May. 



During this time the}' are closely watched, and should anj" of the ova, 

 from want of impregnation, or from anj' other cause, become bad, thej' 

 will turn an opaque white color, and being easily noticed are removed b}' 

 means of forceps, or other instruments adapted for the purpose. Should 

 these white, or dead, eggs be kept too long, they will become putrid, and 

 a fungus will begin to grow upon them ; this would seriously' atfect and 

 destroy all adjoining eggs. 



Should any sediment or other deleterious substance settle upon the 

 ova during the time of hatching, it is immediatel}' washed off b}' sprink- 

 ling water upon them with an ordinary' gardener's watering can. B3' 

 this means they are kept clean and free from filth of all kinds. No frost 

 is allowed to penetrate the building, and the flow of water is regulated 

 at pleasure by taps leading into each of the series of troughs through- 

 out the entire building. At the entrance of each trough perforated 

 screens are placed to prevent the possibility of small fish entering them. 

 In this thoroughly protected state the ova are kept until the young fish 

 emerge from the shell, generalh* in April and May, after which time also, 

 and until the umbilical sac is wholly absorbed, the}' are carefully watched 

 and protected. 



In May and June the fry will have become beautifully developed, 

 active little fish, and should be turned into the rivers or other waters 

 which are required to be restocked ; or at this time they may be placed 

 in ponds of living water, and regularly fed until they become parrs, and 

 afterwards smolts. At this latter stage they make their first migration 

 to the sea, or other large body of water, where they become grilse, and 

 afterwards salmon. 



The modus ojyerancli pursued in the artificial impregnation of fish eggs 

 and the rearing of fry being somewhat minutely described, it only 

 remains now to draw a contrast between the natural and artificial meth- 

 ods of propagating fish. In the latter there is no possibility of losing either 

 the egg or the milt by being swept out of or beyond the pan or artificial 

 bed in which they were placed by hand, as would be the case when laid 

 by the parent fish in the rapid waters of rivers and streams. In the one 

 case a few moments will suflflce to relieve the fish of the whole burden 



